Absorption and luminescence of bismuth ions implanted into CaO and MgO single crystals

The absorption and luminescence spectra of bismuth ions implanted into CaO and MgO have been examined. The results in CaO confirm that spectra hitherto assigned to Bi3+ are due to this ion and show that efficient luminescence in implanted samples does not develop until defects caused by radiation damage are annealed out. This is despite the fact that Bi3+ ions occupy the correct cubic sites after only moderate heat treatment. Implanted MgO shows absorption and emission lines at 336 and 352 nm, respectively. The intensities of the electronic-vibrational lines in emission are unusual and remain to be explained.